Bottle container made of resin and method for manufacturing the same

ABSTRACT

The present invention provides a bottle container made of resin, which comprises a cylindrical barrel with a bottom and a cylindrical neck portion with a diameter smaller than that of the barrel, said bottle container further comprising an upper part and a lower part divided into two parts by dividing at an upper end or a lower end of the barrel, and under the condition that the upper part and the lower part are connected with each other, said two parts are integrated by a cover member for liquid-tightly covering connecting surfaces of said two parts to shield the connecting surfaces from outside and to integrate the two parts with each other.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a bottle container made of resinfor accommodating a liquid substance, said bottle container comprising acylindrical neck portion on an upper end of a cylindrical barrel withbottom, said neck portion having a diameter smaller than that of thebarrel. The invention also relates to a method for manufacturing saidbottle container. For instance, the invention relates to a bottlecontainer made of resin for accommodating a liquefied cosmetic materialsuch as mascara liquid and also to a method for manufacturing saidbottle container.

[0002] In the past, blow molding method has been used to manufacture abottle container made of resin, which comprises a cylindrical barrelwith bottom and a cylindrical neck portion having a diameter smallerthan that of the barrel (e.g. JP-A-2001-113589). However, by this blowmolding method, it has been only possible to manufacture a bottlecontainer with portions other than the neck portion having 3 mm inthickness at the most. It has been difficult to mold a bottle containerof about 5 mm in thickness. Also, by this blow molding method, it hasbeen difficult to mold a container, which has a partially thickerportion. In this respect, it has been customary to use glass as thematerial to manufacture a container, which has thicker bottom or abarrel relatively thick and giving visual impression of a high qualityproduct. For instance, glass is normally used to manufacture a bottlecontainer for liquid cosmetic material (e.g. Japanese Patent Application9-215521).

[0003] However, in the bottle container made of glass as describedabove, surface irregularities or distortion often occurs on innersurface of the container during molding process, and it has beendifficult to produce bottle containers with the same and uniform volume.When the bottle containers for liquid cosmetic material different involume are used, liquid surface is not maintained at constant level evenwhen the same quantity of liquid cosmetic material is filled in eachcontainer by using a filling machine. If the liquid level in a containeris lower than that of the other container, it looks as if the volume ofthe liquid cosmetic material inside the container is less than that ofthe other container. For this reason, it has been customary to fill theliquid cosmetic material into the bottle container by manual operationuntil the liquid level reaches a predetermined position in each of thebottle containers. However, the manual filling operation of the liquidcosmetic material requires troublesome procedure and is evenuneconomical because higher material cost is required when the liquidcosmetic material is expensive.

SUMMARY OF THE INVENTION

[0004] It is an object of the present invention to provide a bottlecontainer made of resin, in which a part of the container, e.g. bottomor barrel, is relatively thick (about 5 mm in thickness) to give visualimpression of high quality product, and which is uniform in volume, andwhen a constant quantity of liquid is filled in the container, theliquid surface is maintained always at a constant level. The inventionalso provides a method for manufacturing the bottle container with theabove features.

[0005] The bottle container made of resin according to the presentinvention comprises an upper part and a lower part, divided at an upperend or at a lower end of a cylindrical barrel with bottom, and under thecondition where the upper part and the lower part are connected witheach other, a cover member is used to cover the connecting surfaces ofthe upper part and the lower part so that the connecting surfaces can beshielded from outside.

[0006] Also, the method for manufacturing the bottle container made ofresin according to the present invention comprises the steps ofseparately molding an upper part and a lower part of the bottlecontainer, using resin by injection molding, the upper part and thelower part of the bottle container being divided at an upper end or at alower end of a cylindrical barrel with bottom, and under the conditionthat the upper part and the lower part are connected with each other,injecting a molten resin to connecting portions of the two parts byinsert molding, cooling and solidifying it to prepare a cover member,and liquid-tightly covering the upper part and the lower part by thecover member so that connecting surfaces of these parts are shieldedfrom outside and the two parts are integrated with each other.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1 is a longitudinal sectional view, showing a bottlecontainer made of resin before an upper part thereof is connected with alower part thereof;

[0008]FIG. 2 is a longitudinal sectional view of a bottle container madeof resin when the upper part is connected with the lower part thereof;

[0009]FIG. 3 is a partially enlarged longitudinal sectional view ofconnecting portion of the bottle container made of resin;

[0010]FIG. 4 is a schematical partial longitudinal sectional view whenthe upper part and the lower part of the bottle container are set in aninsert molding machine;

[0011]FIG. 5 is a schematical partial longitudinal sectional view whenmembers of the insert molding machine are moved so that molten resin canbe injected;

[0012]FIG. 6 is a schematical partial longitudinal sectional view whenthe molten resin is injected;

[0013]FIG. 7 is a schematical partial longitudinal sectional view whenthe injection of the molten resin has been completed and the members ofthe insert molding machine have been brought back to initial position;and

[0014]FIG. 8 to FIG. 14 each represents a partially enlargedlongitudinal sectional view of another embodiment of the invention whenthe upper part and the lower part of the bottle container made of resinare connected with each other.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] As shown in FIG. 1 and FIG. 2, a bottle container 1 made ofpolyethylene terephthalate (hereinafter referred as “PET”) comprises acylindrical barrel 3 with a bottom 2, and a cylindrical neck portion 4with a diameter smaller than that of the barrel 3. At an upper end ofthe barrel 3, the bottle container is divided to two parts in verticaldirection, i.e. an upper part 5 and a lower part 6. Annular recesses 7and 8 are provided respectively on outer periphery of a lower end of theupper part 5 and of an upper end of the lower part 6. The annular recess7 comprises a lower end collar 11 of the upper part 5 and a hook-shapedannular projection 9 arranged on lower surface of the lower end collar11 and being bent in outward direction. The annular recess 8 comprisesan upper end shoulder 12 of the lower part 6 and a hook-shaped annularprojection 10 arranged on upper surface of the upper end shoulder 12 andbeing bent in outward direction. Each of the annular projections 9 and10 constitutes an end of the division. The outermost edges of the lowerend collar 11 and the upper end shoulder 12, i.e. the outermost edges ofthe annular recesses 7 and 8, are aligned with outer periphery of thebarrel 3. On the lower surface of the annular projection 9 of the upperpart 5, there is provided an engaging annular projection 15, which canbe engaged with inner peripheral surface of the annular projection 10 ofthe lower part 6.

[0016] Under the condition that the annular projections 9 and 10 areconnected with each other (as shown in FIG. 2), an annular cover member14 made of PET (FIG. 3) is liquid-tightly engaged in an annularconnecting groove 13 defined by the annular recesses 7 and 8 so that theconnecting surfaces of the upper part 5 and the lower part 6 can beshielded from outside. As a result, the parts 5 and 6 are integratedwith each other and make up a bottle container 1. On outer peripheralsurface of the neck 4 of the upper part 5, a male screw is formed sothat a cap (not shown) is to be screwed on it.

[0017] In the bottle container 1 with the above arrangement, theengaging projection 15 of the upper part 5 is engaged tightly with innerperiphery of the annular projection 10 of the lower part 6, and thecover member 14 is engaged in the annular connecting groove 13. Thus,the annular projections 9 and 10 positioned in the depth of the annularconnecting groove 13 are caught from above and underneath, and the upperpart 5 and the lower part 6 are reliably integrated with each other. ThePET material, i.e. the resin, used in the upper part 5, the lower part6, and the cover member 14 has high adhesive property due to fusion andis difficult to be peeled off, and this is suitable for insert moldingas described above.

[0018] Next, description will be given on a method to manufacture thebottle container 1. First, brief description will be given on the insertmolding machine to be used in a process to integrate the upper part 5with the lower part 6. As shown in FIG. 4 to FIG. 7, an insert moldingmachine 16 comprises a molten resin feeding member 19 and a metal moldbase 23. The molten resin feeding member 19 plays a role in supporting afeeding nozzle 17 and a positioner 18, and it is movable in verticaldirection. The metal mold base 23 is provided with a support member 20for supporting the upper part 5 and the lower part 6 connected with eachother, and it is provided with a part of sliding metal molds 21 and 22,which can be opened or closed by relatively sliding in horizontaldirection and can be separated from each other. When closed, the upperpart 5 and the lower part 6 at supporting position can be squeezed fromlateral direction. One of the sliding metal molds, e.g. the slidingmetal mold 21 (shown on the left in the figure), is provided with agate. When the metal molds are closed (See FIG. 5 and FIG. 6), a baseend 24 a of the gate 24 is connected with the lower end of the feedingnozzle 17 of the molten resin feeding member 19, and a gate port 24 b atthe end of the gate 24 is set to a position to engage with the annularconnecting groove 13 at the connecting ends of the upper part 5 and thelower part 6.

[0019] Next, description will be given on each process of the method formanufacturing the bottle container 1.

[0020] (Manufacturing Process 1)

[0021] First, the upper part 5 and the lower part 6 divided near theupper end of the barrel 3 are molded by an injection molding machine(not shown) using PET as resin material. In the molding process, theannular recess 7 defined by the lower end collar 11 and by thehook-shaped annular projection 9 is formed at the dividing end of theupper part 5, and the annular recess 8 defined by the upper shoulder 12and the hook-shaped annular projection 10 is formed on outer peripheryof the dividing end of the lower part 6.

[0022] (Manufacturing Process 2)

[0023] Next, on the support member 20 of the metal mold base 23 of theinsert molding machine 16 under standby condition (i.e. the conditionwhere the molten resin feeding member 19 is moved up and the slidingmetal molds 21 and 22 are opened), the upper part 5 and the lower part 6prepared in the manufacturing process 1 are connected in verticaldirection (see FIG. 4).

[0024] (Manufacturing Process 3)

[0025] When the insert molding machine 16 is operated, the molten resinfeeding member 19 is moved down, and the positioner 18 is engaged withthe upper end of the upper part 5 to determine the positions of theupper part 5 and the lower part 6 connected with each other. The slidingmetal molds 21 and 22 are slid in direction to move closer to each otherand are closed (FIG. 5). Under this condition, the lower end of thefeeding nozzle 17 of the molten resin feeding member 16 is connectedwith the base end 24 a of the gate 24, and the gate port 24 b of thegate 24 is moved to a position to face the annular groove 13 of theupper part 5 and the lower part 6.

[0026] (Manufacturing Process 4)

[0027] Then, molten PET is sent into the feeding nozzle 17 of the moltenresin feeding member 19, and it is fed into the annular connectinggroove 13 from the gate port 24 b via the gate 24 (FIG. 6).

[0028] (Manufacturing Process 5)

[0029] Next, when the molten PET is fed completely into the annularconnecting groove 13, the molten metal feeding member 19 is moved up tothe standby position. The sliding metal molds 21 and 22 are slid in thedirection to be separated from each other, and the insert moldingmachine 16 is set to the standby position (FIG. 7).

[0030] (Manufacturing Process 6)

[0031] When a certain time has elapsed under the standby condition, themolten PET is solidified in the annular connecting groove 13, and anannular cover member 14 is formed. The dividing ends of the upper part 5and the lower part 6 are tightly attached to each other and areintegrated, and the bottle container 1 is prepared. The bottle container1 is then taken out.

[0032] According to the method for manufacturing the bottle container 1as described above, the upper part 5 and the lower part 6 are separatelymolded by the injection molding machine, and these are integrated byinsert molding. Thus, it is possible to easily manufacture the bottlecontainer 1 made of resin having a neck portion 4 with a barrel 3 ofabout 5 mm in thickness, which has been difficult to manufacture by theconventional blow molding method. In the bottle container 1 manufacturedby this method, PET is used as the molten resin for forming the upperpart 5, the lower part 6, and the cover member 14. As a result, thecover member 14 after solidifying is firmly deposited on inner surfaceof the annular connecting groove 13 of the upper part 5 and the lowerpart 6. This ensures good adhesive property and rigid construction ofthe product, which is not easily peeled off.

[0033] The present invention is not limited to the embodiment asdescribed above. For instance, the connecting portion of the upper part5 and the lower part 6 divided into two parts at the upper end of thebarrel 3 may be designed as shown in each of FIG. 8 to FIG. 10.

[0034] In the arrangement as shown in FIG. 8, an annular projection 115a is provided on outer periphery of the lower end of an engagingprojection 115 of the upper part 105, and an annular groove 110 aengaged with the annular projection 115 a is provided on innerperipheral surface of the annular projection 110 of the lower part 106.By this arrangement, the upper part 105 and the lower part 106 are moretightly attached to each other. The cover member 114 is liquid-tightlyengaged with the annular connecting groove 113 so that the connectingsurfaces of the parts 105 and 106 are shielded from outside.

[0035] In the arrangement shown in FIG. 9, each of the annularprojections 209 and 210 is designed in straight form instead ofhook-shaped design. There is no annular recess, and the annularconnecting groove 213 is defined by outer peripheral surface of anannular projection 209, which is continuous to the connecting surfacesof the upper part 205 and the lower part 6, and by an upper end surfaceof an annular projection 210. The cover member 214 is liquid-tightlyengaged in the annular connecting groove 213 so that the connectingsurfaces of the parts 5 and 6 are shielded from outside.

[0036] Further, in the arrangement shown in FIG. 10, an annularprojection 309 is arranged on outer peripheral surface of the upper part305 so that it is protruded in radial direction. There is no annularrecess, and the annular connecting groove 313 is defined by upper endsurface of annular projections 309 and 310, which are continuous to theconnecting surfaces of the parts 305 and 306. The cover member 314 isliquid-tightly engaged in the annular connecting groove 313 so that theconnecting surfaces of the parts 305 and 306 are shielded from outside.

[0037] The connecting portion of the upper part 5 and the lower part 6of the present invention may be designed in such manner that these partsare divided into two parts at the lower end of the barrel 3 instead ofthe upper end of the barrel 3.

[0038] In the arrangement shown in FIG. 11, the upper part 405 comprisesa neck portion (not shown) and a barrel 403, and the lower part 406comprises only a bottom portion 402. A gate port 424 b for the insertmolding is formed on the lower surface of outer edge of the bottomportion 402. An annular projection 415 a is provided on inner peripheryof the engaging projection 415 of the lower part 406, and an annulargroove 409 a engaged with the annular projection 415 a is arranged oninner peripheral surface of the annular projection 409 of the upper part405. The arrangement of the annular recesses 407 and 408 and the annularconnecting groove 413 as well as the cover member 414 is the same as thearrangement shown in FIG. 8.

[0039] Also, in the arrangement shown in FIG. 12, an annular projection509 of the upper part 505 and an annular projection 510 of the lowerpart 506 are designed in straight form instead of hook-shaped design.There is no annular recess, and the annular connecting groove 513 isdefined by outer peripheral surface of the annular projection 510 and bythe upper end surface of the annular projection 509. The arrangement ofthe annular connecting groove 513 and the cover member 514 is the sameas that of FIG. 9.

[0040] In the arrangement shown in FIG. 13, annular projections 609 and610 are designed in straight form, and outer diameter of the bottomportion 602 of the lower part 606 is smaller than outer diameter of thebarrel 603 of the upper part 605. Neither annular recess nor annularconnecting groove is provided. A cover member 614 in form of a lid withouter edge protruding upward is provided to shield the connectingsurfaces of the upper part 605 and the lower part 606.

[0041] In the arrangement shown in FIG. 14, an annular projection 709 isformed on outer peripheral surface of a bottom portion 702 of the lowerpart 706 by extending the bottom portion 702 in radial direction.Neither annular recess nor annular connecting groove is provided. Acover member 714 in form of a disk is engaged with inner peripheralsurface of the lower end of the upper part 705 so that it is tightlyattached on the lower surface of the lower part 706, and the covermember is used to shield the connecting surfaces of the upper part 705and the lower part 706 from outside.

[0042] As described above, in the bottle container according to thepresent invention, the upper part and the lower part separately moldedare integrated by the use of a cover member. Thus, it is possible tomanufacture a bottle container with a barrel of about 5 mm in thickness.Compared with the conventional type bottle container made of glass, theproduct is uniform in volume and coloring is easy to perform. Becausethe dividing portion is set to the upper end or the lower end of thebottle container, the product is rigid and sturdy in construction.

[0043] When an engaging projection to engage with a dividing end isarranged on the other dividing end of the upper part or the lower part,the upper part and the lower part can be integrated with each other inmore reliable connecting condition. This is helpful to achieve higherstrength of the bottle container.

[0044] Further, in the method for manufacturing the bottle containeraccording to the present invention, the upper part and the lower partare molded separately, and these are then integrated by a cover memberin the insert molding procedure. Thus, it is possible to easilymanufacture a bottle container made of resin with a barrel of about 5 mmin thickness, which has a neck portion with a diameter smaller than thatof the barrel and which is difficult to manufacture by the conventionalblow molding procedure. Also, the dividing portion of the two parts isset to the upper end or the lower end of the bottle container. Thisprevents bending or deflection in inward direction when the cover memberis molded and also contributes to the improvement of strength of theproduct.

What is claimed is:
 1. A bottle container made of resin, comprising acylindrical neck portion and a cylindrical barrel with a bottom, saidneck portion being provided on a upper end of said barrel and having adiameter smaller that of the barrel, said bottle container furthercomprises an upper part and a lower part divided in vertical directionat an upper end or a lower end of the barrel, and under the conditionthat the upper part and the lower part are connected with each other, acover member is used to liquid-tightly cover the connecting surfaces ofsaid two parts so that the connecting surfaces are shield from outside,and to integrate connecting surfaces of said two parts.
 2. A bottlecontainer made of resin, comprising a cylindrical neck portion and acylindrical barrel with a bottom, said neck portion being provided on aupper end of said barrel and having a diameter smaller that of thebarrel, said bottle container further comprises an upper part and alower part divided in vertical direction at an upper end or a lower endof the barrel, and under the condition that the upper part and the lowerpart are connected with each other, a cover member made of resin isliquid-tightly attached to an annular connecting grove formed by asurface continuous to the connecting surfaces of said two parts so thatthe connecting surfaces of said two parts can be shielded from outside.3. A bottle container made of resin, comprising a cylindrical neckportion and a cylindrical barrel with a bottom, said neck portion beingprovided on an upper end of said barrel and having a diameter smallerthat of the barrel, the container is further divided to an upper partand a lower part divided at an upper end or a lower end of the barrel,and annular recesses are formed on the upper part and the lower partrespectively, and under the condition where the lower end of said upperpart is connected with the upper end of the lower part, a cover membermade of resin is liquid-tightly placed into an annular connecting groovedefined by the annular recesses of said parts so that connectingsurfaces of these parts are shielded from outside, and the two parts areintegrated with each other.
 4. A bottle container made of resinaccording to claim 3, wherein there is provided an annular engagingprojection on one of connecting ends of either the upper part or thelower part, and said engaging projection is engaged on the other of theconnecting ends.
 5. A method for manufacturing a bottle container madeof resin, comprising a cylindrical neck portion and a cylindrical barrelwith a bottom, said neck portion having a diameter smaller than that ofthe barrel, said method comprising the steps of separately forming anupper part and a lower part by dividing the barrel at an upper end or ata lower end thereof to an upper part and a lower part by injectionmolding of resin, and under the condition where dividing ends of theupper part and the lower part are connected with each other, injecting amolten resin by insert molding and cooling and solidifying to prepare acover member so that connecting surfaces of said parts areliquid-tightly covered to shield the connecting surface from outside,and integrating the upper part and the lower part by the cover member.6. A method for manufacturing a bottle container made of resin,comprising a cylindrical neck portion and a cylindrical barrel with abottom, said neck portion having a diameter smaller than that of thebarrel, said method comprising the steps of separately forming an upperpart and a lower part by dividing the barrel at an upper end or at alower end thereof to an upper part and a lower part by injection moldingof resin, and under the condition where dividing ends of the upper partand the lower part are connected with each other, further injecting amolten resin by insert molding into an annular connecting groove definedby a surface continuous to the connecting surfaces of said parts, theconnecting surfaces of said parts being shielded from outside andliquid-tightly covered, and cooling and solidifying said resin toprepare a cover member, and integrating the upper part and the lowerpart by said cover member.
 7. A method for manufacturing a bottlecontainer made of resin, comprising a cylindrical neck portion and acylindrical barrel with a bottom, said neck portion having a diametersmaller than that of the barrel, said method comprising the steps ofseparately forming an upper part and a lower part having an annularrecesses on outer periphery of said dividing ends, dividing said barrelat an upper end or a lower end thereof into an upper part and a lowerpart by injection molding of resin, and under the condition wheredividing ends of the upper part and the lower part are connected witheach other, injecting a molten resin into an annular connecting grooveformed by annular recesses of said parts by insert molding, cooling andsolidifying to prepare a cover member, and integrating said upper partand said lower part by said cover member.